Method and apparatus for processing hybrid automatic repeat request process in communication system

ABSTRACT

Method and apparatus for processing hybrid automatic repeat request process in communication system are disclosed. An operation method of a communication node comprises configuring one or more hybrid automatic repeat request (HARQ) groups; and deploying at least one HARQ process identifier (ID) in each of the one or more HARQ groups, wherein each of the one or more HARQ groups includes a HARQ memory group, a memory controller group controlling the HARQ memory group, and a decoder group performing a decoding based on data stored in the HARQ memory group by accessing the HARQ memory group through the memory controller group. Therefore, performance of the communication system may be enhanced.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priorities to Korean Patent Applications No.10-2017-0024850 filed on Feb. 24, 2017 and No. 10-2018-0017952 filed onFeb. 13, 2018 in the Korean Intellectual Property Office (KIPO), theentire contents of which are hereby incorporated by reference.

BACKGROUND 1. Technical Field

The present disclosure relates to a hybrid automatic repeat request(HARQ) technique in a communication system, and more specifically, to atechnique for independently processing a HARQ process in order tosatisfy requirements of high data throughput and low latency.

2. Related Art

In a communication system, a data packet may be transmitted from atransmitter (e.g., a base station) to a receiver (e.g., a terminal) overa radio channel. An error may occur in the data packet received at thereceiver depending on the state of the radio channel (e.g., the qualitychange of the radio channel). A forward error correction (FEC) techniquemay be used to recover the reception error. If the FEC technique is usedin the communication system, the transmitter may transmit a data packetcontaining redundancy and the receiver may recover the reception errorusing the redundancy in the presence of the reception error in thereceived data packet.

Also, an automatic repeat request (ARQ) technique may be used to recoverthe reception error. When the ARQ technique is used in the communicationsystem, the transmitter may transmit a data packet including a cyclicredundancy check (CRC), and the receiver may check the presence of anerror based on the CRC included in the received data packet. If there isno error in the received data packet, the receiver may transmit anacknowledgment (ACK) to the transmitter. On the other hand, if there isan error in the received data packet, the receiver may transmit anegative ACK (NACK) to the transmitter. The transmitter that receivedthe NACK may retransmit the same data packet to the receiver.

Also, a hybrid ARQ (HARQ) technique, which is a combination of the FECtechnique and the ARQ technique, may be used in the communicationsystem. A HARQ retransmission procedure may be performed based on achase combining (CC) scheme or an incremental redundancy (IR) scheme.When the HARQ retransmission procedure according to the CC scheme isperformed, the transmitter may repeatedly transmit the same data packet.In this case, the receiver may reproduce the original data packet bycombining the same received data packets. When the HARQ retransmissionprocedure according to the IR scheme is performed, the transmitter maytransmit data packets having different redundancy versions (RVs). Thereceiver may reproduce the original data packet by combining thereceived data packets having different RVs.

Meanwhile, when the HARQ retransmission procedure is performed, atransport block (TB) corresponding to an HARQ process identifier may bestored in an HARQ memory (e.g., a HARQ buffer). The size of the HARQmemory may increase in order to meet the requirements of high datathroughput in the communication systems. However, when the size of theHARQ memory increases, the requirements of low latency may not besatisfied. Therefore, there is a need for the HARQ technique to meet therequirements of high data throughput and low latency both.

SUMMARY

Accordingly, embodiments of the present disclosure provide a method andan apparatus for independently processing a HARQ process in acommunication system.

In order to achieve the objective of the present disclosure, anoperation method of a first communication node may comprise configuringone or more hybrid automatic repeat request (HARQ) groups; and deployingat least one HARQ process identifier (ID) in each of the one or moreHARQ groups, wherein each of the one or more HARQ groups includes a HARQmemory group, a memory controller group controlling the HARQ memorygroup, and a decoder group performing a decoding based on data stored inthe HARQ memory group by accessing the HARQ memory group through thememory controller group, and wherein an deployment interval of HARQprocess IDs belonging to each of the one or more HARQ groups is equal toor greater than a HARQ processing time of a single HARQ process. Here, aminimum value of the HARQ processing time may be a processing time ofthe HARQ memory.

Here, parameters used for configuring the one or more HARQ groups arereceived through at least one of a radio resource control (RRC)signaling procedure, a system information transmission procedure, and acontrol information transmission procedure.

Here, the one or more HARQ groups are configured based on a total numberof the one or more HARQ groups, a total number of HARQ process IDsbelonging to the one or more HARQ groups, a total number of decodersbelonging to the one or more HARQ groups, an deployment interval betweenof the HARQ groups, at least one HARQ process ID deployed in the one ormore HARQ groups, and the HARQ processing time.

Here, total methods for deploying the HARQ process ID may not bedisclosed in the present invention because the methods for deploying theHARQ process ID may be infinite. Therefore, for easy of explanation,embodiments of the present invention may be explained in the mostcomplicated situation in terms of the HARQ. The most complicatedsituation may be that the maximum allowable HARQ process IDs aredeployed and management operations for retransmission are necessary perthe deployed total HARQ process IDs because negative acknowledgements(NACKs) are occurred in the deployed total HARQ process IDs. In thiscase, even when it is assumed that the HARQ process ID per atransmission time interval (TTI) is deployed by an increase manner ordecrease manner, it does not loss the generality because the maximumallowable HARQ process IDs are deployed. Therefore, the embodiments ofthe present inventions may be explained in the most complicatedsituation if there is no mention. However, this assumption may be forease of explanation, and the embodiments of the present invention maynot be limited to the above-described assumption.

Here, when the HARQ processing time is L, a total number of the one ormore HARQ groups is K, an deployment interval of the HARQ group is s, atotal number of the HARQ process IDs is N, and an arbitrary HARQ processID among N HARQ process IDs is j, an embodiment, that the HARQ processID is deployed in the HARQ group so as to obtain the deployment intervalwhich is equal to or greater than L TTI, may be that HARQ process IDshaving a same result of ‘j mod K’ are deployed in same HARQ group. Here,when ‘N mod K=0,’ ‘min(S)=k’ may be satisfied because a minimum value ofthe deployment interval S of the HARQ process ID belonging to same HARQgroup, and ‘K=min(S)≥L’ may be satisfied by the above-describedassumption that the deployment interval S of the HARQ group is equal toor greater than the HARQ processing time L. Therefore, when K HARQgroups is selected to satisfy ‘K≥L,’ the HARQ process ID may be deployedin a specific HARQ group so that the deployment interval S of same HARQgroups may be equal to or greater than L TTI.

Here, when ‘N mod K≠0’, it is possible to operate in various ways.

First, a method of deploying HARQ process IDs in an HARQ group may beused as an existing method. In this case, the minimum value of thedeployment interval S of the HARQ groups may be set to N mod K.Therefore, K may be selected such that ‘N mod K≥L’ is satisfied. When ‘Nmod K=αK (0<α<1)’ is satisfied, K may be selected such that ‘K≥L/α’ issatisfied. Because implementation complexity increases as the number ofHARQ groups, which is K, increases, it is advantageous to keep K assmall as possible, K may be set to the minimum value when K is selectedso that α is as close as possible to 1.

In the case of ‘N mod K≠0,’ K may be selected so that α is as close aspossible to 1 as another method. When an operation comparing ‘N mod K’with K/2 is added to the operation for deploying the HARQ process IDs inthe HARQ group, the minimum value of the deployment interval of the HARQgroup may be always more than K/2. When the operation for deploying theHARQ process ID #j in the HARQ group ‘j mod K’ is only used, ‘0<α<1’ issatisfied. When the operation comparing ‘N mod K’ with K/2 is added tothe operation for deploying the HARQ process ID #j in the HARQ group ‘jmod K,’ the HARQ group is deployed to keep always ‘½≤α<1.’

When ‘N mod K≥K/2’ is satisfied, the HARQ process ID #j may be deployedin the HARQ group #(j mod K) among N HARQ process IDs. In this case, theminimum value of the deployment interval S of the HARQ group may be ‘Nmod K,’ and K may be equal to or more than K/2. When ‘N mod K<K/2’ issatisfied, ‘floor (N/K)*K’ HARQ process IDs that can be grouped by Kamong the N HARQ process IDs may be deployed in the HARQ group #(j modK), and remaining N mod K HARQ IDs may be deployed in the HARQ group#((K/2)+(j mod K)). In this case, the minimum value of the deploymentinterval of the HARQ group may be (K/2+(j mod K)) and always more thanK/2. Therefore, in the case of ‘N mod K≠0,’ ‘min(S)=K/2’ may besatisfied because the minimum value of the deployment interval S of theHARQ group is equal to or more than K/2. Because ‘min(S)=K/2≥L’ issatisfied, the number of HARQ groups K may be selected so that ‘K≥2L’ issatisfied.

In general, in the case of ‘N mod K<K/x (x is a natural number equal toor more than 2),’ the deployment interval of the HARQ process may bealways equal to or more than K/x when remaining N mod K HARQ process IDsare deployed in the HARQ group #(K*β+(j mod K)) (β may be a real numberequal to or more than 1/x and equal to or less than 1).

Here, emphasizing again, the above-described methods for grouping theHARQ process IDs are just embodiments according to the presentinvention. As above-described embodiments, because the methods fordeploying the HARQ process IDs are numerous, it is impossible to explainall of them individually. Therefore, an embodiment for obtaining thedeployment interval of L TTI or more per the HARQ group in the situationthat the HARQ process ID operates according to TTI as the increasemanner or decrease manner is a method for grouping the HARQ process IDusing a result of ‘j mod K.’ The key points may be that the HARQ processIDs having the deployment interval according to a specific situation aredeployed in same HARQ group and the deployment interval S of the HARQprocess IDs belonging to same HARQ group is more than the HARQprocessing time L. Therefore, if there are different deploymentintervals between HARQ process IDs, the deployment interval S of theHARQ process IDs belonging to same HARQ group may be grouped equal to ormore than L TTI based on another form (e.g., another equation, anothertable, or separate signaling, etc.) which does not depend on the resultof ‘j mod K.’

In summary, the HARQ process IDs may be mapped to the HARQ group by theHARQ group mapping function, and then the HARQ process IDs may begrouped. Here, inputs of the HARQ group mapping function may be the HARQprocess ID and the HARQ processing time, and outputs of the HARQ groupmapping function may be the HARQ group. In this case, the deploymentinterval of the HARQ groups may be equal to or more than the HARQprocessing time. The above-described embodiments may be that the HARQgroup mapping function is ‘j mod K.’

In addition, if there is no mention in all situations described in thepresent invention, it is always possible to freely use a method that thedeployment interval of the HARQ group is set to more than L TTI usingempty TTI.

Here, the operation method of the first communication node may comprisereceiving a transport block from a second communication node; performinga demodulation operation on the transport block; performing a demappingoperation on the demodulated transport block; storing the demappedtransport block in the HARQ memory group; and performing a decodingoperation on the demapped transport block stored in the HARQ memorygroup.

Here, the demapped transport block may be stored in the HARQ memorygroup belonging to the HARQ group in which a HARQ process ID of thedemapped transport block is deployed.

Here, the step for performing the decoding operation may furthercomprise identifying a HARQ memory group storing the demapped transportblock based on a HARQ process ID of the demapped transport block;obtaining the demapped transport block from the identified HARQ memorygroup; and performing a decoding operation on the obtained demappedtransport block.

In order to achieve the objective of the present disclosure, anoperation method of a first communication node may comprise configuringparameters to be used for configuring one or more hybrid automaticrepeat request (HARQ) groups; and transmitting the parameters to asecond communication node; wherein each of the one or more HARQ groupsmay include a HARQ memory group, a memory controller group controllingthe HARQ memory group, and a decoder group performing a decoding basedon data stored in the HARQ memory group by accessing the HARQ memorygroup through the memory controller group, and wherein the parametersmay include at least one of a total number of the one or more HARQgroups, a total number of HARQ process IDs belonging to the one or moreHARQ groups, a total number of decoders belonging to the one or moreHARQ groups, an deployment interval of the one or more HARQ groups, atleast one HARQ process ID deployed in the one or more HARQ groups, and aHARQ processing time of a single HARQ process.

Here, the parameters may be transmitted through at least one of a radioresource control (RRC) signaling procedure, a system informationtransmission procedure, and a control information transmissionprocedure.

Here, a deployment interval of HARQ process IDs belonging to each of theone or more HARQ groups may be equal to or greater than the HARQprocessing time.

Here, when the HARQ processing time is L, a total number of the one ormore HARQ groups is K, the deployment interval of the HARQ group is S, atotal number of HARQ process IDs is N, and an arbitrary HARQ process IDamong N HARQ process IDs is j, HARQ process IDs having a same result of(j mod K) are deployed in a same HARQ group so that the deploymentinterval is equal to or more than L TTI.

In order to achieve the objective of the present disclosure, acommunication node may comprise a processor; and a memory storing atleast one command which is executed by the processor, wherein the atleast one command may be executed to configure one or more hybridautomatic repeat request (HARQ) groups; and arrange at least one HARQprocess identifier (ID) in each of the one or more HARQ groups, whereineach of the one or more HARQ groups may include a HARQ memory group, amemory controller group controlling the HARQ memory group, and a decodergroup performing a decoding based on data stored in the HARQ memorygroup by accessing the HARQ memory group through the memory controllergroup, and wherein an deployment interval of HARQ process IDs belongingto each of the one or more HARQ groups may be equal to or greater than aHARQ processing time of a single HARQ process.

Here, the one or more HARQ groups may be configured based on a totalnumber of the one or more HARQ groups, a total number of the HARQprocess IDs belonging to the one or more HARQ groups, a total number ofdecoders belonging to the one or more HARQ groups, a deployment intervalof the one or more HARQ groups, at least one HARQ process ID deployed inthe one or more HARQ groups, and the HARQ processing time.

Here, when the HARQ processing time is L, a total number of the one ormore HARQ groups is K, the deployment interval of the HARQ group is S, atotal number of HARQ process IDs is N, and an arbitrary HARQ process IDamong N HARQ process IDs is j, HARQ process IDs having a same result of(j mod K) are deployed in a same HARQ group so that the deploymentinterval is equal to or more than L TTI.

Here, when ‘N mod K=0,’ ‘min(S)=k’ may be satisfied because a minimumvalue of the deployment interval S of the HARQ process ID belonging tosame HARQ group, and ‘K=min(S)≥L’ may be satisfied by theabove-described assumption that the deployment interval S of the HARQgroup is equal to or greater than the HARQ processing time L. Therefore,when K HARQ groups is selected to satisfy ‘K≥L,’ the HARQ process ID maybe deployed in a specific HARQ group so that the deployment interval Sof same HARQ groups may be equal to or greater than L TTI.

Here, when ‘N mod K≠0’, it is possible to operate in various ways.

First, a method of deploying HARQ process IDs in an HARQ group may beused as an existing method. In this case, the minimum value of thedeployment interval S of the HARQ groups may be set to N mod K.Therefore, K may be selected such that ‘N mod K≥L’ is satisfied. When ‘Nmod K=αK (0<α<1)’ is satisfied, K may be selected such that ‘K≥L/α’ issatisfied. Because implement complexity increases as the number of HARQgroups K increase, it is advantageous to keep K as small as possible, Kmay be set to the minimum value when K is selected so that α is as closeas possible to 1.

As another method, K may be selected so that α is as close as possibleto 1. When an operation comparing ‘N mod K’ with K/2 is added to theoperation for deploying the HARQ process IDs in the HARQ group, theminimum value of the deployment interval of the HARQ group may be alwaysmore than K/2. When the operation for deploying the HARQ process ID #jin the HARQ group ‘j mod K’ is only used, ‘0<α<1’ is satisfied. When theoperation comparing ‘N mod K’ with K/2 is added to the operation fordeploying the HARQ process ID #j in the HARQ group ‘j mod K,’ the HARQgroup is deployed to keep always ‘½≤α<1.’ When ‘N mod K≥K/2’ issatisfied, the HARQ process ID #j may be deployed in the HARQ group #(jmod K) among N HARQ process IDs. In this case, the minimum value of thedeployment interval S of the HARQ group may be ‘N mod K,’ and K may beequal to or more than K/2. When ‘N mod K<K/2’ is satisfied, ‘floor(N/K)*K’ HARQ process IDs that can be grouped by K among the N HARQprocess IDs may be deployed in the HARQ group #(j mod K), and remainingN mod K HARQ IDs may be deployed in the HARQ group #((K/2)+(j mod K)).In this case, the minimum value of the deployment interval of the HARQgroup may be (K/2+(j mod K)) and always more than K/2. Therefore, in thecase of ‘N mod K≠0,’ ‘min(S)=K/2’ may be satisfied because the minimumvalue of the deployment interval S of the HARQ group is equal to or morethan K/2. Because ‘min(S)=K/2≥L’ is satisfied, the number of HARQ groupsK may be selected so that ‘K≥2L’ is satisfied.

In general, in the case of ‘N mod K<K/x (x is a natural number equal toor more than 2),’ the deployment interval of the HARQ process may bealways equal to or more than K/x when remaining N mod K HARQ process IDsare deployed in the HARQ group #(K*β+(j mod K)) (β may be a real numberequal to or more than 1/x and equal to or less than 1).

According to the present invention, an HARQ memory for storing atransport block corresponding to a HARQ process identifier can bedivided into one or more HARQ memory groups considering the executiontime for processing the corresponding HARQ process. Also, a memorycontroller group and a decoder group (or encoder group) corresponding toeach of one or more HARQ memory groups may be configured. With thisconfiguration, since the processing operation of the HARQ process isperformed independently, a conflict between the processing operations ofthe HARQ processes may not occur. Therefore, the requirements of highdata throughput and low latency can be satisfied in the communicationsystem, and the size of HARQ memory can also be relatively reduced. As aresult, the performance of the communication system can be improved.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments of the present disclosure will become more apparent bydescribing in detail embodiments of the present disclosure withreference to the accompanying drawings, in which:

FIG. 1 is a conceptual diagram illustrating a first embodiment of acommunication system;

FIG. 2 is a block diagram illustrating a first embodiment of acommunication node constituting a communication system;

FIG. 3 is a block diagram illustrating a first embodiment of thetransceiver included in the communication node of FIG. 2;

FIG. 4 is a block diagram illustrating a configuration of“decoder-to-memory” in a procedure for processing HARQ processes;

FIG. 5 is a block diagram illustrating a second embodiment of aconfiguration of “decoder-to-memory” in a procedure for processing HARQprocess;

FIG. 6 is a timing chart illustrating a first embodiment of HARQ groupdeployment;

FIG. 7 is a timing chart illustrating a second embodiment of HARQ groupdeployment;

FIG. 8 is a timing chart illustrating a third embodiment of HARQ groupdeployment;

FIG. 9 is a timing chart illustrating a fourth embodiment of HARQ groupdeployment;

FIG. 10 is a timing chart illustrating a fifth embodiment of HARQ groupdeployment;

FIG. 11 is a timing chart illustrating a sixth embodiment of HARQ groupdeployment;

FIG. 12 is a flow chart illustrating a first embodiment of a method ofprocessing a HARQ process;

FIG. 13 is a conceptual diagram illustrating a first embodiment of aconfiguration of HARQ groups when ‘N mod K≠0’ and ‘N mod K≥K/2’;

FIG. 14 is a conceptual diagram illustrating a first embodiment of aconfiguration of HARQ groups when ‘N mod K≠0’ and ‘N mod K<K/2’; and

FIG. 15 is a block diagram illustrating a third embodiment of aconfiguration of “decoder-to-memory” in a procedure for processing HARQprocess.

DETAILED DESCRIPTION

Embodiments of the present disclosure are disclosed herein. However,specific structural and functional details disclosed herein are merelyrepresentative for purposes of describing embodiments of the presentdisclosure, however, embodiments of the present disclosure may beembodied in many alternate forms and should not be construed as limitedto embodiments of the present disclosure set forth herein.

Accordingly, while the present disclosure is susceptible to variousmodifications and alternative forms, specific embodiments thereof areshown by way of example in the drawings and will herein be described indetail. It should be understood, however, that there is no intent tolimit the present disclosure to the particular forms disclosed, but onthe contrary, the present disclosure is to cover all modifications,equivalents, and alternatives falling within the spirit and scope of thepresent disclosure. Like numbers refer to like elements throughout thedescription of the figures.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, these elements should notbe limited by these terms. These terms are only used to distinguish oneelement from another. For example, a first element could be termed asecond element, and, similarly, a second element could be termed a firstelement, without departing from the scope of the present disclosure. Asused herein, the term “and/or” includes any and all combinations of oneor more of the associated listed items.

It will be understood that when an element is referred to as being“connected” or “coupled” to another element, it can be directlyconnected or coupled to the other element or intervening elements may bepresent. In contrast, when an element is referred to as being “directlyconnected” or “directly coupled” to another element, there are nointervening elements present. Other words used to describe therelationship between elements should be interpreted in a like fashion(i.e., “between” versus “directly between,” “adjacent” versus “directlyadjacent,” etc.).

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the presentdisclosure. As used herein, the singular forms “a,” “an” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“comprises,” “comprising,” “includes” and/or “including,” when usedherein, specify the presence of stated features, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this present disclosure belongs.It will be further understood that terms, such as those defined incommonly used dictionaries, should be interpreted as having a meaningthat is consistent with their meaning in the context of the relevant artand will not be interpreted in an idealized or overly formal senseunless expressly so defined herein.

Hereinafter, embodiments of the present disclosure will be described ingreater detail with reference to the accompanying drawings. In order tofacilitate general understanding in describing the present disclosure,the same components in the drawings are denoted with the same referencesigns, and repeated description thereof will be omitted.

Hereinafter, wireless communication networks to which exemplaryembodiments according to the present disclosure will be described.However, wireless communication networks to which exemplary embodimentsaccording to the present disclosure are applied are not restricted towhat will be described below. That is, exemplary embodiments accordingto the present disclosure may be applied to various wirelesscommunication networks. Here, a communication system may mean thecommunication network.

FIG. 1 is a conceptual diagram illustrating a first embodiment of acommunication system.

Referring to FIG. 1, a communication system 100 may comprise a pluralityof communication nodes 110, 121, 122, 123, 124, and 125. Also, thecommunication system 100 may comprise a core network (e.g., a servinggateway (S-GW), a packet data network (PDN) gateway (P-GW), a mobilitymanagement entity (MME), and the like). The plurality of communicationnodes may support 4^(th) generation (4G) communication (e.g., long termevolution (LTE), LTE-advanced (LTE-A)), or 5^(th) generation (5G)communication defined in the 3^(rd) generation partnership project(3GPP) standard.

For example, the plurality of communication nodes may support at leastone communication protocol among a code division multiple access (CDMA)based communication protocol, a wideband CDMA (WCDMA) basedcommunication protocol, a time division multiple access (TDMA) basedcommunication protocol, a frequency division multiple access (FDMA)based communication protocol, an orthogonal frequency divisionmultiplexing (OFDM) based communication protocol, an orthogonalfrequency division multiple access (OFDMA) based communication protocol,a single carrier FDMA (SC-FDMA) based communication protocol, anon-orthogonal multiple access (NOMA) based communication protocol, anda space division multiple access (SDMA) based communication protocol.

Meanwhile, each of the plurality of communication nodes may have thefollowing structure.

FIG. 2 is a block diagram illustrating a first embodiment of acommunication node constituting a communication system.

Referring to FIG. 2, a communication node 200 may comprise at least oneprocessor 210, a memory 220, and a transceiver 230 connected to thenetwork for performing communications. Also, the communication node 200may further comprise an input interface device 240, an output interfacedevice 250, a storage device 260, and the like.

Each component included in the communication node 200 may communicatewith each other as connected through a bus 270. However, each of thecomponents included in the communication node 200 may be connected tothe processor 210 via a separate interface or a separate bus rather thanthe common bus 270. For example, the processor 210 may be connected toat least one of the memory 220, the transceiver 230, the input interfacedevice 240, the output interface device 250, and the storage device 260via a dedicated interface.

The processor 210 may execute a program stored in at least one of thememory 220 and the storage device 260. The processor 210 may refer to acentral processing unit (CPU), a graphics processing unit (GPU), or adedicated processor on which methods in accordance with embodiments ofthe present disclosure are performed. Each of the memory 220 and thestorage device 260 may be constituted by at least one of a volatilestorage medium and a non-volatile storage medium. For example, thememory 220 may comprise at least one of read-only memory (ROM) andrandom access memory (RAM).

Referring again to FIG. 1, in the communication system 100, the basestation 110 may form a macro cell or a small cell, and may be connectedto the core network through an ideal backhaul or a non-ideal backhaul.The base station 110 may transmit signals received from the core networkto the corresponding terminals 121, 122, 123, 124 and 125, and transmitsignals received from the terminals 121, 122, 123, 124, and 125 to thecore network. The plurality of terminals 121, 122, 123, 124, and 125 maybelong to the cell coverage of the base station 110. The plurality ofterminals 121, 122, 123, 124 and 125 may be connected to the basestation 110 by performing a connection establishment procedure with thebase station 110. The plurality of terminals 121, 122, 123, 124, and 125may communicate with the base station 110 after being connected to thebase station 110.

Also, the base station 110 may perform multiple-input multiple-output(MIMO) transmission (e.g., single user (SU) MIMO, multi user (MU) MIMO,massive MIMO etc.), coordinated multipoint (CoMP) transmission, carrieraggregation (CA) transmission, unlicensed band transmission,device-to-device communication (D2D) (or proximity services (ProSe)),and the like. Each of the plurality of terminals 121, 122, 123, 124, and125 may perform an operation corresponding to the base station 110, anoperation supported by the base station 110, and the like.

The base station 110 may also be referred to as a Node B, an evolvedNode B (eNB), a base transceiver station (BTS), a radio remote head(RRH), a transmission reception point (TRP), a radio unit (RU), aroadside unit (RSU), a radio transceiver, an access point, an accessnode, or the like. Each of the plurality of terminals 121, 122, 123, 124and 125 may also be referred to as a terminal, a user equipment (UE), anaccess terminal, a mobile terminal, a station, a subscriber station, amobile station, a portable subscriber station, a node, a device, anon-broad unit (OBU), or the like.

Next, methods for independently processing a hybrid automatic repeatrequest (HARQ) process in a communication system will be described. Evenwhen a method (e.g., transmission or reception of a data packet)performed at a first communication node among communication nodes isdescribed, the corresponding second communication node may perform amethod (e.g., reception or transmission of the data packet)corresponding to the method performed at the first communication node.That is, when an operation of a terminal is described, the correspondingbase station may perform an operation corresponding to the operation ofthe terminal. Conversely, when an operation of the base station isdescribed, the corresponding terminal may perform an operationcorresponding to the operation of the base station.

FIG. 3 is a block diagram illustrating a first embodiment of thetransceiver included in the communication node of FIG. 2, and FIG. 4 isa block diagram illustrating a configuration of “decoder-to-memory” in aprocedure for processing HARQ processes.

Referring to FIGS. 3 and 4, the transceiver 230 of the communicationnode 200 may include a transmitter 231, a receiver 233, an antenna 235,and the like. The transmitter 231 may include an encoder 231-1, a mapper231-3, a modulator 231-5, an inverse fast Fourier transform (IFFT)231-7, a digital-to-analog converter (DAC) 231-9, and the like. Theresults processed by the components 231-1, 231-3, 231-5, 231-7, and231-9 included in the transmitter 231 may be stored in the memory 220.The receiver 233 may include a decoder 233-1, a demapper 233-3, ademodulator 233-5, an FFT 233-7, an analog-to-digital converter (ADC)233-9, and the like. The results processed by the components 233-1,233-3, 233-5, 233-7, and 233-9 included in the receiver 233 may bestored in the memory 220.

When a HARQ retransmission procedure is performed, received data packetsmay be stored in a HARQ memory 223 for each HARQ process identifier(ID). For example, when a HARQ process ID is set for each transportblock (TB), the HARQ process ID of the TB #0 may be set to ‘0’, the HARQprocess ID of the TB #1 may be set to ‘1’, and the HARQ process ID ofthe TB #(N−1) may be set to ‘N−1’. Here, N may be an integer equal to orgreater than zero.

The HARQ memory 223 may belong to the memory 220 of the communicationnode 200 and the results processed by the demapper 233-3 may be storedin the HARQ memory 223. A space indicated by the HARQ process ID #0 inthe HARQ memory 223 may be a space in which the TB #0 (e.g., loglikelihood ratio (LLR) values for the TB #0) corresponding to the HARQprocess ID #0 is stored, a space indicated by the HARQ process ID #1 inthe HARQ memory 223 may be a space in which the TB #1 (e.g., LLR valuesfor the TB #1) corresponding to the HARQ process ID #1 is stored, and aspace indicated by the HARQ process ID #(N−1) in the HARQ memory 223 maybe a space in which the TB #(N−1) (e.g., LLR values for the TB #(N−1))corresponding to the HARQ process ID #(N−1) is stored.

The decoder 233-1 may be composed of one or more decoders 233-1-0 to233-1-(M−1). Here, M may be an integer of 0 or more. Each of the one ormore decoders 233-1-0 to 233-1-(M−1) may be connected to the HARQ memory223 via a memory controller 225, may obtain a TB (e.g., LLR values for aTB) corresponding to a HARQ process ID from the HARQ memory 223, andperform decoding on the obtained TB. The memory controller 225 may bereferred to as a ‘memory arbiter’ or a ‘memory interface’. When one ormore memory access requests are received from the one or more decoders233-1-0 to 233-1-(M−1), the memory controller 225 may sequentiallyprocess the one or more memory access requests, so that the one or moredecoders 233-1-0 to 233-1-(M−1) can access the HARQ memory 223 atdifferent times.

Meanwhile, when the HARQ retransmission procedure is performed, theoperation of the transmitter 231 may correspond to the operation of thereceiver 233 described above. In this case, one or more decoders 233-1-0through 233-1-(M−1) may correspond to one or more encoders, and the HARQmemory 223 may store the results processed by the one or more encoders.

In the HARQ retransmission procedure, the TBs corresponding to theentire HARQ process IDs may be managed by one HARQ memory 223. In orderto satisfy the requirements of high data throughput and low latency interms of the HARQ memory 223, a high capacity HARQ memory and asimultaneous accessible HARQ memory may be required.

The HARQ retransmission procedure may be controlled by a receiver (e.g.,the receiver 233), and a retransmission operation may be performed foreach HARQ process ID (e.g., for each TB). The size of the TB mayincrease with an increase in data throughput, and thus the HARQ memory223 having large capacity may be required. Also, when a time divisionduplex (TDD) type frame is used due to a lack of frequency resources,the number of HARQ process IDs managed in the HARQ retransmissionprocedure may increase because a bidirectional link may not exist. Forthis reason, the HARQ memory 223 having the large capacity may berequired.

However, as the size of the HARQ memory 223 increases, a delay time(e.g., a delay time of processing the HARQ process) increases, which maymake it difficult to increase the speed of the circuit. Also, sincethere is a limit to increase the clock of the circuit, the high datathroughput and low latency requirements may not be satisfied. As thesize of the HARQ memory 223 increases, the cost of the HARQ memory 223may increase, so that the implementation cost of the circuit mayincrease.

Also, a short delay may be required in the 5G communication compared tothe conventional communication (e.g., 4G communication). If the size ofthe TB increases to satisfy the high data throughput requirement, thedelay time may increase. In this case, it may be considered to reducethe transmission time interval (TTI) duration to meet the low latencyrequirement. That is, it may be necessary to speed up the circuit toprocess the TB with the increased size within the reduced TTI duration.There is a limitation in performance improvement due to the speeding upof the circuit, so that a scheme of using one or more decoders 233-1-0to 233-1-(M−1) configured in parallel may be considered.

In order for each of the one or more decoders 233-1-0 to 233-1-(M−1) toperform the operation of processing the HARQ process (hereinafter,referred to as ‘HARQ processing operation’), it may be necessary toprocess memory access requests that occur simultaneously in the memorycontroller 225. For processing of the memory access requests, thecomplexity of the memory controller 225 and the cost of the HARQ memory223 may increase. However, when one or more memory access requests occursimultaneously, a conflict between HARQ memory access requests inaccordance with one or more memory access requests may occur in the HARQmemory 223. In order to address this problem, the memory controller 225may generate one HARQ memory access request corresponding to one memoryaccess request through an arbitration operation if one or more memoryaccess requests are present. According to this, since the HARQprocessing operations are sequentially performed, the delay time can beincreased.

That is, the large capacity HARQ memory 223 may be needed to meet therequirement of high data throughput. Also, in order to meet therequirement of low latency, one or more decoders 233-1-0 to 233-1-(M−1)may be needed, and the arbitration scheme of the memory access requestsoccurring simultaneously by the one or more decoders 233-1-0 to233-1-(M−1) may be required.

FIG. 5 is a block diagram illustrating a second embodiment of aconfiguration of “decoder-to-memory” in a procedure for processing HARQprocess.

Referring to FIG. 5, one or more HARQ groups (e.g., HARQ groups #0 to#(K−1)) may be configured, and each of the one or more HARQ groups mayinclude a HARQ memory group, a memory controller group, and a decodergroup. The HARQ memory group may store TBs corresponding to respectiveHARQ process IDs, the memory controller group may control the HARQmemory group, and the decoder group may access the HARQ memory groupthrough the memory controller group to decode the TBs stored in the HARQmemory group. For example, the HARQ group #0 may include a HARQ memorygroup #0, a memory controller group #0, and a decoder group #0, and theHARQ group #(K−1) may include a HARQ memory group #(K−1), a memorycontroller group #(K−1), and a decoder group #(K−1).

The HARQ group, the HARQ memory group, the memory controller group, andthe decoder group (or encoder group) may be configured based on thefollowing parameters (hereinafter referred to as ‘HARQ parameters’), andmethods for configuring the HARQ parameters will be described in detail.

-   -   K: the total number of HARQ groups configured in the transmitter        or the receiver    -   N_(K): the total number of HARQ process IDs belonging to the        HARQ group #k (e.g., HARQ group #0 to #(K−1))    -   N: the total number of HARQ process IDs    -   M_(K): the total number of decoders (or encoders) belonging to        the HARQ group #k (e.g., group #0 to #(K−1))    -   M: the total number of decoders    -   S: deployment interval of HARQ group (on a TTI basis)    -   HARQ process ID in HARQ group    -   L: execution time of HARQ processing operation (e.g., delay time        according to HARQ processing operation) (on a TTI basis)

Meanwhile, in order to minimize simultaneous memory access requests, oneor more decoders may be configured as one decoder group, and a HARQmemory group and a memory controller group for each of the decodergroups may be configured. The configuration of the “encoder-to-memory”may be the same as or similar to the configuration of the“decoder-to-memory” shown in FIG. 5. For example, a decoder group maycorrespond to an encoder group (or an entity group performing L2functions) of the transmitter, and the encoder group may correspond toone or more encoders (e.g., entities performing L2 functions).

In FIG. 4, since each of the decoders 233-1-0 to 233-1-(M−1) does notknow the HARQ process ID to be processed by itself, one or more memoryaccess requests may be generated at the same time. On the other hand, inFIG. 5, since HARQ memory groups (e.g., HARQ process IDs belonging tothe same HARQ memory group) assigned to the respective decoder groupsare configured, physically-separated HARQ memories may be configured.For example, HARQ memories corresponding to ranges of HARQ process IDsto be processed by the respective decoder groups may be configured, andeach of the decoder groups may independently perform the HARQ processingoperation. Thus, conflicts between memory access requests can beminimized.

Also, when the interval of the HARQ process IDs belonging to each of theHARQ memory groups is set to be longer than the execution time of theHARQ processing operation (e.g., the delay time of the HARQ processingoperation), the HARQ processing operations in each HARQ group may beperformed independently so that the complexity of the memory controllergroup can be reduced.

The Total Number (K) of HARQ Groups

The number K of HARQ groups may be configured within a range thatsatisfies the following condition 1 below when N mod K=0, and the numberK of HARQ groups may be configured with a range that satisfies thefollowing condition 2 below when N mode K≠0.

-   -   Condition 1: L≤K≤M    -   Condition 2: L*K/(N mod K)≤K≤M or xL≤K≤M (x is a natural number        equal to or greater than 2)

Also, the total number of each of HARQ memory groups, memory controllergroups, and decoder groups may be the same as the total number of HARQgroups.

The Total Number (N) of HARQ Process IDs

The total number (N) of HARQ process IDs may be configured within themaximum value defined in the specification. For example, when themaximum value of the number of HARQ process IDs in the specification isset to 16, the total number N of HARQ process IDs may be set to 16 orless. Also, the total number of HARQ process IDs may be interpreted asthe total number of HARQ processes IDs deployed to perform HARQoperations.

The Total Number (M) of Decoders

The total number (M) of decoders included in the receiver 233 (or thetotal number (M) of encoders included in the transmitter 231) may beconfigured based on the execution time of the HARQ processing operationof the corresponding decoder (or, encoder). In case that the executiontime of the HARQ processing operation for processing a data packetaccording to the maximum amount of transmission corresponds to L TTIs, Mdecoders may be configured in the receiver 233. Also, although theminimum repetition cycle of the decoder group is L TTIs, K HARQ groupsexist, and thus it is also preferable that the decoder group is repeatedevery K TTIs, if possible. Accordingly, the number of decoders Mibelonging to the decoder group #i may be ‘min(Mi)=M/K’. In general, thevalue of min(Mi) should be maintained at 1 or more so that the HARQgroup can be operated favorably. Here, ‘K≤M’ can be satisfied. Since thesum of the number of decoders in HARQ groups is equal to the totalnumber of decoders, ‘ΣMi=M’ can be satisfied.

Deployment (or Assignment) of HARQ Groups

For independent processing of the HARQ processes, the HARQ group may bedeployed as follows.

FIG. 6 is a timing chart illustrating a first embodiment of HARQ groupdeployment.

Referring to FIG. 6, the deployment interval of the same HARQ group maybe 0 TTI, and the HARQ processing operation in the HARQ group #0 may beperformed within one TTI. For example, a processing operation for a HARQprocess belonging to the HARQ group #0 may be performed in TTI #0 andTTI #1. Here, the HARQ process ID number may be sequentially increasedor decreased by one.

FIG. 7 is a timing chart illustrating a second embodiment of HARQ groupdeployment.

Referring to FIG. 7, the deployment interval of the same HARQ group maybe 1 TTI, and the HARQ processing operation in each of the HARQ groups#0 and #1 may be performed within 2 TTIs. For example, a processingoperation for the HARQ process belonging to the HARQ group #0 may beperformed in the TTIs #0 to #1, and a processing operation for the HARQprocess belonging to the HARQ group #1 may be performed in the TTIs #1to #2.

FIG. 8 is a timing chart illustrating a third embodiment of HARQ groupdeployment.

Referring to FIG. 8, the deployment interval of the same HARQ group maybe 2 TTIs, and the HARQ processing operation in each of the HARQ groups#0 to #2 may be performed within 3 TTIs. For example, a processingoperation for the HARQ process belonging to the HARQ group #0 may beperformed in the TTIs #0 to #2, a processing operation for the HARQprocess belonging to the HARQ group #1 may be performed in the TTIs #1to #3, and a processing operation for the HARQ process belonging to theHARQ group #2 may be performed in the TTIs #2 to #4.

Also, in case that MIMO-based spatial multiplexing is performed in thecommunication system, HARQ groups may be set differently for each TB.For example, the HARQ group may be deployed as follows.

FIG. 9 is a timing chart illustrating a fourth embodiment of HARQ groupdeployment.

Referring to FIG. 9, the deployment interval of the same HARQ group maybe 0 TTI, and different HARQ group may be configured for each TB. Forexample, a processing operation for the HARQ process belonging to theHARQ group #0 may be performed in the TB #0, and a processing operationfor the HARQ process belonging to the HARQ group #1 may be performed inthe TB #1.

FIG. 10 is a timing chart illustrating a fifth embodiment of HARQ groupdeployment.

Referring to FIG. 10, the deployment interval of the same HARQ group maybe 1 TTI, and different HARQ groups may be configured for each TB. Forexample, a processing operation for the HARQ process belonging to theHARQ group #0 may be performed in the TTI #0 of the TB #0, and aprocessing operation for the HARQ process belonging to the HARQ group #2may be performed in TTI #1 of the TB #0. Also, a processing operationfor the HARQ process belonging to the HARQ group #1 may be performed inthe TTI #0 of the TB #1, and a processing operation for the HARQ processbelonging to the HARQ group #3 may be performed in TTI #1 of the TB #1.

FIG. 11 is a timing chart illustrating a sixth embodiment of HARQ groupdeployment.

Referring to FIG. 11, the deployment interval of the same HARQ group maybe 2 TTIs, and different HARQ groups may be configured for each TB. Forexample, a processing operation for the HARQ process belonging to theHARQ group #0 may be performed in the TTI #0 of the TB #0, a processingoperation for the HARQ process belonging to the HARQ group #2 may beperformed in TTI #1 of the TB #0, and a processing operation for theHARQ process belonging to the HARQ group #4 may be performed in TTI #2of the TB #0. Also, a processing operation for the HARQ processbelonging to the HARQ group #1 may be performed in the TTI #0 of the TB#1, a processing operation for the HARQ process belonging to the HARQgroup #3 may be performed in TTI #1 of the TB #1, and a processingoperation for the HARQ process belonging to the HARQ group #5 may beperformed in TTI #2 of the TB #1.

Also, in the case that spatial multiplexing is performed, even if a HARQgroup is configured for each TB, additional HARQ group may be implicitlyassigned to each TB, and may operate independently of each other. Inother words, even if they are configured as the same HARQ group for eachTB in FIGS. 9 to 11, they may be implicitly regarded as separateindependent HARQ groups.

When a HARQ group is configured for each TB in FIGS. 9 to 11,“decoder-to-memory” may be configured as shown in FIG. 15. That is, aHARQ memory group, a memory controller group, and a decoder group foreach of the TBs in the HARQ group may be configured.

Deployment (or Assignment) of HARQ Process IDs

In case that the number of HARQ groups is K and the number of any HARQprocess ID is j, the HARQ process IDs with the same result from ‘j modK’ may be configured to the same HARQ group (e.g., HARQ memory group).In case that the number of HARQ process IDs is N and ‘N mod K=0’, theexecution interval of HARQ processing operations (e.g., processingoperations of the same HARQ process ID) causing a collision may bemaximized to a multiple of K TTIs.

On the other hand, in case of ‘N mod K≠0’, when the HARQ process ID #jis deployed in the HARQ group #(j mod K), ‘floor (N/K)*K’ HARQ processIDs #j that can be grouped by K among the N HARQ process IDs may bedeployed in the HARQ group #(j mod K), and the deployment intervalbetween the HARQ process ID #j (e.g., one of the HARQ process IDs #jsatisfying ‘floor (j/K)=floor (N/K)’ when the HARQ process IDs aredeployed in a simple increase form for each TTI without an empty TTI)belonging to the last remaining ‘N mod K’ HARQ groups and the HARQprocess ID #j′ (e.g., the HARQ process ID #j′ satisfying ‘floor(j′/K)=0’) belonging to the first HARQ group (e.g., one of the first KHARQ memory groups) that can be further grouped by K may be ‘N mod K’.In case of ‘N mod K≥K/2’, the HARQ process ID #j may be deployed in theHARQ group #(j mod K). In this case, the deployment interval of the sameHARQ groups may always be K/2 or more. That is, in case that ‘N mod K≠0’and ‘N mod K≥K/2’, the configuration of the HARQ groups may be the sameas in FIG. 13. Here, there are the same HARQ groups for each column.

In case of ‘N mod K<K/2’, ‘floor (N/K)*K’ HARQ process IDs #j (e.g., #0to #(floor (N/K)*K−1)) that can be grouped by K among the N HARQ processIDs may be deployed in the HARQ group #(j mod K), and the remaining ‘Nmod K’ HARQ process IDs #j may be deployed in the HARQ group #((K/2)+(jmod K)). In this case, the minimum value of the deployment intervalbetween ‘N mod K’ last HARQ process IDs #j remaining after being groupedby K and the HARQ process IDs #j′ belonging to the first HARQ group thatcan be further grouped by K again may be (K/2+(j mod K)), which isalways larger than K/2. Therefore, ‘min(S)=K/2’ is established becausethe minimum value of the deployment interval S of the HARQ groups forall Ks is equal to or larger than K/2 in the state of ‘N mod K≠0’.Accordingly, ‘min (S)=K/2≥L’ should be established, and in this case,the number K of HARQ groups may be selected to satisfy ‘K≥2L’. That is,in case that ‘N mod K≠0’ and ‘N mod K<K/2’, the configuration of theHARQ groups may be the same as in FIG. 14. Here, there are the same HARQgroups for each column. In this case, since the minimum deploymentinterval of the HARQ process ID is K/2, not K, the selection range of Kmay be reduced. Therefore, it may be advantageous that the total numberN of HARQ process IDs is set to a multiple of K.

In general, in the case of ‘N mod K<K/x (x is a natural number of 2 ormore)’, if (N mod K) remaining HARQ process IDs are allocated to HARQgroup #(K*β+(j mod K)) (β is an arbitrary real number equal to or largerthan 1/x and equal to or smaller than 1), the deployment interval of theHARQ processes may always be equal to or larger than K/x.

The deployment interval of HARQ process IDs may be set based on othermethods other than the method described above. The deployment intervalof the HARQ process IDs may be set according to the operation status ofthe HARQ retransmission procedure (e.g., the execution time of the HARQprocessing operation of the decoder or the encoder). The deploymentinterval of the HARQ process IDs may be larger than the execution timeof the HARQ processing operation. Here, it will be emphasized again thatthe methods of grouping the HARQ process IDs are merely one example forease of explanation. As described above, the method of deploying theHARQ process IDs cannot be fully explained because of a large number ofsituations. Accordingly, in the case where the HARQ process ID isoperated in the form of a simple increase or a simple decrease accordingto the TTI, which is assumed for ease of explanation, an example forobtaining the deployment interval of L TTIs or more for each HARQ groupis a method of grouping HARQ process IDs using the result of ‘j mod K’.

The above situation assumes that the HARQ process ID #j is located atTTI #t (t=j). If there is an empty TTI or does not operate in asequential increase form according to the situation, the HARQ process ID#j may be deployed at TTI #t (t #j). In this case, it may be necessaryto consider the TTI #t together with the HARQ process ID #j in order toobtain the deployment interval for each HARQ process ID. In this case,the deployment interval may be determined based on the TTI #t in theHARQ RTT instead of the HARQ process ID #j, the HARQ group may begrouped, and the HARQ process #j deployed in the corresponding TTI maybe stored. That is, the HARQ process ID #j may be interpreted as theHARQ process ID #j′ of the t-th TTI in the HARQ RTT according to thesituation.

That is, the essential point of the present invention is to arrange theHARQ process IDs having the deployment interval in the same HARQ groupaccording to the situation, and to operating HARQ by setting thedeployment interval S of the HARQ process IDs belonging to the same HARQgroup to be longer than the execution time L of the HARQ processingoperation. Therefore, if there is an deployment interval between HARQprocess IDs, HARQ process IDs belonging to the same HARQ group may begrouped so that the deployment interval S of them becomes equal to orgreater than L TTIs through another form (e.g., another formula, atable, or separate signaling, etc.).

In general, a HARQ process ID may be mapped to a HARQ group by a HARQgroup mapping function, and the HARQ process IDs may be groupedaccordingly. Here, inputs to the HARQ group mapping function may be theHARQ process ID and the HARQ process processing time, and outputs of theHARQ group mapping function may be the HARQ groups. In this case, thedeployment interval of the HARQ groups may be equal to or longer thanthe HARQ process processing time. The above-described embodiment may bean example of the case that the HARQ group mapping function is ‘j modK’. If the spatial multiplexing is performed, the TB number may also beadded as the input to the HARQ group mapping function. Also, when theHARQ groups are changed with time, the TTI number may also be added asthe input to the HARQ group mapping function.

For example, in case of ‘N=8’ and ‘K=4’, the HARQ process ID in the HARQgroup may be configured as shown in Table 1 below. When the executiontime of the HARQ processing operation is 1 TTI, the deployment intervalof HARQ process IDs belonging to the same HARQ group may be set to beequal to or larger than 1.

TABLE 1 HARQ group HARQ process ID numbers number belong to HARQ group 00, 2 1 1, 3 2 4, 6 3 5, 7

Execution Time (L) of HARQ Processing Operation

The execution time L of the HARQ processing operation may be set basedon the performance of the decoder (or encoder), the size of the TBcorresponding to the HARQ process ID, the LLR bit width, and the like.

Meanwhile, methods of setting the HARQ parameters (e.g., K, N, M, S,HARQ process ID in the HARQ group, L, and the like) described above maybe as follows.

-   -   setting method #1: The HARQ parameters may be predefined in the        specification, and the communication node (e.g., transmitter and        receiver) may configured the HARQ groups based on the HARQ        parameters defined in the specification, and process HARQ        processes based on the configured HARQ groups.    -   setting method #2: ‘deployment interval of HARQ group’ and ‘HARQ        process ID in HARQ group’ may be signaled to a communication        node (e.g., transmitter or receiver). The communication node may        estimate (or calculate) the remaining HARQ parameters (e.g., K,        N, M, S) based on the signaled HARQ parameters, configure the        HARQ groups based on the signaled HARQ parameters and estimated        (or calculated) HARQ parameters, and process HARQ processes        based on the configured HARQ groups. Alternatively, the        communication node may configure the HARQ groups based on the        signaled HARQ parameters and the remaining HARQ parameters        defined in the specification, and may process the HARQ processes        based on the configured HARQ groups.    -   setting method #3: N may be defined in the specification, in        which case the communication node may estimate (or calculate)        the remaining HARQ parameters (e.g., M, K, S, etc.) based on N.        Therefore, the communication node may configure the HARQ groups        based on the HARQ parameters defined in the standard and the        estimated (or calculated) HARQ parameters, and may process the        HARQ processes based on the configured HARQ groups.    -   setting method #4: The transmitter may notify at least one of        the HARQ parameters to the receiver through at least one of a        radio resource control (RRC) signaling procedure, a system        information transmission procedure, and a transmission procedure        of control information (e.g., downlink control information        (DCI)). The receiver may configure the HARQ groups based on the        at least one HARQ parameter received from the transmitter, and        may process the HARQ processes based on the configured HARQ        groups. Here, the HARQ parameters may be set by the transmitter.    -   setting method #5: the receiver may provide information (e.g.,        the number of decoders of the receiver, the HARQ process        processing time, and the like) that the transmitter does not        know among the information necessary for setting the HARQ groups        at the transmitter, and the transmitter may configure the HARQ        parameters by identifying the configuration of the receiver        through the provided information. The transmitter may        selectively inform the receiver of necessary information (e.g.,        mapping relations between the HARQ process IDs and the HARQ        groups or mapping relations between the TTI numbers and the HARQ        groups) among the configured HARQ parameters.

FIG. 12 is a flow chart illustrating a first embodiment of a method ofprocessing a HARQ process.

Referring to FIG. 12, each of the transmitter and the receiver may beconfigured to be the same as or similar to the communication node 200shown in FIG. 2. Also, the transceiver of the transmitter and thereceiver may be the same or similar to the transceiver 230 shown in FIG.3. In the downlink communication, the transmitter may be a base station,and the receiver may be a terminal. In the uplink communication, thetransmitter may be a terminal and the receiver may be a base station. InD2D communication, the transmitter may be a first terminal, and thereceiver may be a second terminal.

Each of the transmitter and the receiver may configure one or more HARQgroups based on the HARQ parameters (S1200). The HARQ parameters mayinclude K, N, M, HARQ group deployment interval, HARQ process ID in HARQgroup, execution time of HARQ processing operation, and the like. TheHARQ parameters may be set based on the setting methods #1 to #4described above, and the HARQ group may be configured to be the same asor similar to the HARQ group shown in FIG. 5. Also, in the step S1200,HARQ process IDs may be deployed (or allocated) to each of the one ormore HARQ groups.

The transmitter may transmit a TB (e.g., a data packet) for each HARQprocess ID to the receiver (S1210). The receiver may receive the TB fromthe transmitter and may perform a demodulation operation on the TB(S1220). Also, the receiver may perform a demapping operation on thedemodulated TB (S1230), and store the demapped TB in the HARQ memorygroup (S1240). Here, the demapped TB may be LLR values. The receiver(e.g., the demapper 233-3 of the receiver) may determine the HARQ memorygroup in which the demapped TB is to be stored based on the HARQ processID of the demapped TB. For example, if the number of the HARQ process IDof the demapped TB belongs to 0 to N₀−1, the receiver (e.g., thedemapper 233-3 of the receiver) may store the demapped TB in the HARQmemory group #0 of FIG. 5.

The receiver (e.g., the decoder 233-1 of the receiver) may perform adecoding operation on the demapped TB stored in the HARQ memory group(S1250). For example, the receiver (e.g., the decoder 233-1 of thereceiver) may identify the HARQ memory group in which the demapped TBcorresponding to the HARQ process ID to be processed is stored, acquirethe demapped TB from the corresponding HARQ memory group by performing amemory access request to the identified HARQ memory group, and perform adecoding operation on the acquired demapped TB. If the number of theHARQ process ID to be processed belongs to 0 to N₀−1, the receiver(e.g., the decoder 233-1 of the receiver) may make a memory accessrequest to the memory controller group #0 of FIG. 5, acquire thedemapped TB corresponding to the HARQ process ID by accessing the HARQmemory group #0 according to the memory access request, and perform adecoding operation on the acquired demapped TB.

The embodiments of the present disclosure may be implemented as programinstructions executable by a variety of computers and recorded on acomputer readable medium. The computer readable medium may include aprogram instruction, a data file, a data structure, or a combinationthereof. The program instructions recorded on the computer readablemedium may be designed and configured specifically for the presentdisclosure or can be publicly known and available to those who areskilled in the field of computer software.

Examples of the computer readable medium may include a hardware devicesuch as ROM, RAM, and flash memory, which are specifically configured tostore and execute the program instructions. Examples of the programinstructions include machine codes made by, for example, a compiler, aswell as high-level language codes executable by a computer, using aninterpreter. The above exemplary hardware device can be configured tooperate as at least one software module in order to perform theembodiments of the present disclosure, and vice versa.

While the embodiments of the present disclosure and their advantageshave been described in detail, it should be understood that variouschanges, substitutions and alterations may be made herein withoutdeparting from the scope of the present disclosure.

What is claimed is:
 1. An operation method of a first communication nodein a communication system, the operation method comprising: configuringone or more hybrid automatic repeat request (HARQ) groups; and deployingat least one HARQ process identifier (ID) in each of the one or moreHARQ groups, wherein each of the one or more HARQ groups includes a HARQmemory group, a memory controller group controlling the HARQ memorygroup, and a decoder group performing a decoding based on log likelihoodratio (LLR) values for data stored in the HARQ memory group by accessingthe HARQ memory group through the memory controller group, and wherein adeployment interval of HARQ process IDs belonging to each of the one ormore HARQ groups is equal to or greater than a HARQ processing time of asingle HARQ process, wherein the LLR values for the data with a specificHARQ process ID is stored in the HARQ memory group according to thedeployment interval, and the HARQ processing time is a time necessaryfor transmission and reception operations of the data, and wherein thedecoder group generates the LLR values decoding the data with thespecific HARQ process ID received from a second communication node andstores the LLR values for the data in the HARQ memory group in which thespecific HARQ process ID is deployed through the memory controllergroup.
 2. The operation method according to claim 1, wherein parametersused for configuring the one or more HARQ groups are received through atleast one of a radio resource control (RRC) signaling procedure, asystem information transmission procedure, and a control informationtransmission procedure.
 3. The operation method according to claim 1,wherein the one or more HARQ groups are configured based on a totalnumber of HARQ process IDs, a total number of decoders belonging to theone or more HARQ groups, and the HARQ processing time.
 4. The operationmethod according to claim 1, wherein, when an arbitrary HARQ process IDis j, the HARQ processing time is L, a transport block index is b, atransmission time interval (TTI) number is t, and a mapping functionoutputs a HARQ group number based on j, L, b, and t, transport blockshaving a same result of the mapping function are deployed in a same HARQgroup, and wherein each of j, L, b, and t is a positive integer.
 5. Theoperation method according to claim 1, wherein, when a total number ofthe one or more HARQ groups is K and an arbitrary HARQ process ID is j,HARQ process IDs having a same result of (j mod K) are deployed in asame HARQ group, and wherein each of j, K, and N is a positive integer.6. The operation method according to claim 1, wherein an arbitrary HARQprocess ID is j, a total number of the one or more HARQ groups is K, atotal number of HARQ process IDs is N, x is a natural number equal to orgreater than 2, β is a real number equal to or greater than 1/x andequal to or less than 1, and (N mod K)<K/x, each of remaining HARQprocess IDs excluding HARQ process IDs already allocated to HARQ groupsare deployed in a HARQ group #(K*β±(j mod K)), and wherein each of j, K,and N is a positive integer.
 7. The operation method according to claim1, further comprising: receiving a transport block from the secondcommunication node; performing a demodulation operation on the transportblock; performing a demapping operation on the demodulated transportblock; identifying a HARQ memory group storing the demapped transportblock based on a HARQ process ID of the demapped transport block;obtaining the demapped transport block from the identified HARQ memorygroup and combining the obtained transport block; storing the combinedtransport block in the HARQ memory group; and performing a decodingoperation on the combined transport block.
 8. The operation methodaccording to claim 1, wherein the configuring one or more HARQ groupsfurther comprises: transmitting information on a deployment interval foreach HARQ group to the second communication node; receiving, from thesecond communication node, parameters configured based on theinformation on the deployment interval for each HARQ; and configuringthe one or more HARQ groups by using the parameters.
 9. An operationmethod of a first communication node in a communication system, theoperation method comprising: configuring parameters to be used forconfiguring one or more hybrid automatic repeat request (HARQ) groups;and transmitting the parameters to a second communication node; whereineach of the one or more HARQ groups includes a HARQ memory group, amemory controller group controlling the HARQ memory group, and a decodergroup performing a decoding based on log likelihood ratio (LLR) valuesfor data stored in the HARQ memory group by accessing the HARQ memorygroup through the memory controller group, and wherein the parametersincludes at least one of a total number of the one or more HARQ groups,a total number of HARQ process IDs belonging to the one or more HARQgroups, a total number of decoders belonging to the one or more HARQgroups, a deployment interval of the one or more HARQ groups, at leastone HARQ process ID deployed in the one or more HARQ groups, and a HARQprocessing time of a single HARQ process, wherein a deployment intervalof the HARQ process IDs belonging to each of the one or more HARQ groupsis equal to or greater than the HARQ processing time, wherein the LLRvalues for the data with a specific HARQ process ID is stored in theHARQ memory group according to the deployment interval of the HARQprocess IDs, and the HARQ processing time is a time necessary fortransmission and reception operations of the data, and wherein thedecoder group generates the LLR values decoding the data with thespecific HARQ process ID and stores the LLR values for the data in theHARQ memory group in which the specific HARQ process ID is deployedthrough the memory controller group.
 10. The operation method accordingto claim 9, wherein the parameters are configured based on informationon the deployment interval of each HARQ group which is received from thesecond communication node.
 11. The operation method according to claim9, wherein the parameters are transmitted through at least one of aradio resource control (RRC) signaling procedure, a system informationtransmission procedure, and a control information transmissionprocedure.
 12. The operation method according to claim 9, wherein, whenan arbitrary HARQ process ID is j, the HARQ processing time is L, atransport block index is b, a transmission time interval (TTI) number ist, and a mapping function outputs a HARQ group number based on j, L, b,and t, transport blocks having a same result of the mapping function aredeployed in a same HARQ group, and wherein each of j, L, b, and t is apositive integer.
 13. The operation method according to claim 9,wherein, when a total number of the one or more HARQ groups is K, atotal number of HARQ process IDs is N, and an arbitrary HARQ process IDamong N HARQ process IDs is j, HARQ process IDs having a same result of(j mod K) are deployed in a same HARQ group, and wherein each of K, N,and j is a positive integer.
 14. The operation method according to claim9, wherein an arbitrary HARQ process ID is j, a total number of the oneor more HARQ groups is K, a total number of HARQ process IDs is N, x isa natural number equal to or greater than 2, β is a real number equal toor greater than 1/x and equal to or less than 1, and (N mod K)<K/x, eachof remaining HARQ process IDs excluding HARQ process IDs allocated toHARQ groups are deployed in a HARQ group #(K*β±(j mod K)), and whereineach of j, K and N is a positive integer.
 15. A communication node in acommunication system, comprising: a processor; and a memory storing atleast one command which is executed by the processor, wherein the atleast one command is executed to configure one or more hybrid automaticrepeat request (HARQ) groups and arrange at least one HARQ processidentifier (ID) in each of the one or more HARQ groups, wherein each ofthe one or more HARQ groups includes a HARQ memory group, a memorycontroller group controlling the HARQ memory group, and a decoder groupperforming a decoding based on log likelihood ratio (LLR) values fordata stored in the HARQ memory group by accessing the HARQ memory groupthrough the memory controller group, and wherein a deployment intervalof HARQ process IDs belonging to each of the one or more HARQ groups isequal to or greater than a HARQ processing time of a single HARQprocess, wherein the LLR values for the data with a specific HARQprocess ID is stored in the HARQ memory group according to thedeployment interval, and the HARQ processing time is a time necessaryfor transmission and reception operations of the data, and wherein thedecoder group generates the LLR values decoding the data with thespecific HARQ process ID received from a second communication node andstores the LLR values for the data in the HARQ memory group in which thespecific HARQ process ID is deployed through the memory controllergroup.
 16. The communication node according to claim 15, wherein the oneor more HARQ groups are configured based on a total number of decodersbelonging to the one or more HARQ groups, and the HARQ processing time.17. The communication node according to claim 15, wherein, when anarbitrary HARQ process ID is j, the HARQ processing time is L, atransport block index is b, a transmission time interval (TTI) number ist, and a mapping function outputs a HARQ group number based on j, L, b,and t, transport blocks having a same result of the mapping function aredeployed in a same HARQ group, and wherein each of j, L, b, and t is apositive integer.
 18. The communication node according to claim 15,wherein an arbitrary HARQ process ID is j, a total number of the one ormore HARQ groups is K, a total number of HARQ process IDs is N, x is anatural number equal to or greater than 2, β is a real number equal toor greater than 1/x and equal to or less than 1, and (N mod K)<K/x, eachof remaining HARQ process IDs excluding HARQ process IDs alreadyallocated to HARQ groups are deployed in a HARQ group #(K*β±(j mod K)),and wherein each of j, K, and N is a positive integer.
 19. Thecommunication node according to claim 15, wherein, when the one or moreHARQ groups are configured, the at least one command is further executedto transmit information on a deployment interval for each HARQ group tothe second communication node; receive, from the second communicationnode, parameters configured based on the information on the deploymentinterval for each HARQ; and configure the one or more HARQ groups byusing the parameters.